The polypeptide hormone prolactin modulates a wide diversity of biologic actions including fetal lung maturation and transport of water across the amnion. Studies of the regulation of the human prolactin gene have been limited in part by the relative lack of sufficient amounts of human pituitaries throughout normal stages of physiologic development. Recent studies have shown that the cells of the human decidua have the capacity to synthesize and secrete prolactin during different phases of the normal menstrual cycle and during pregnancy. Thus this tissue might provide a ready source of tissue for more detailed studies of the regulation of the human prolactin gene. There do appear to be some unique features to this decidual model however that will also make it an interesting site to study, as the well described modulators of pituitary prolactin release appear to have little influence on decidual prolactin secretion, prolactin is not packaged in secretory granules but is found in the post-microsomal supernatant and the primary biologic action of this hormone appears to be directed locally rather than at a site distant to its site of secretion. It is thus the purpose of this proposal to develop training in molecular biology through an integrated program of didactic courses, formal and informal seminars and supervised research experiences to aid Dr. Rebecca D. Jackson in making the transition from clinical training status to independent investigation. The research experiences outlined for this proposed program shall be directed at defining first the model of decidual prolactin gene expression in contrast to that of the pituitary (Phase I) and then through detailed studies of the regulation of prolactin gene expression in this extra pituitary site. These studies shall also look at the role of the second messenger systems in regulating peptide modulation of the prolactin gene. This project shall then lay the groundwork for more detailed studies into prolactin control and shall allow RDJ the knowledge for conducting independent investigation in protein biochemistry and molecular biology of the endocrine system.